I hope it's the right forum, surely it is a bug.Firefox did an update this morning, and when I tried to login to my bank website later, it didn't know the login nor the password. After a little research it appeared that there was only ONE login/password in the profile, one that I changed yesterday. After a lot of trials and searching I found a backup from a year ago, and those profile files were accepted by Firefox, so I now have recovered all logins for which the password has not been changed over the last year, and also not anyone newer than 1 year. I expect a few problems coming up in the next week or so.

I have used this feature for at least 3 years without any problem, so how can this happen. The feature is very useful, but if it is not reliable it becomes instantly useless. Does Firefox keep a secret backup somewhere or is there any other solution? I have synced firefox with my phone, and the phone still remembered some passwords, but I don't see how I can recover from my phone back to my laptop either.

This is the solution for the logins.json becoming corrupt whereby the user's passwords were inaccessible, but you can use the same troubleshooting steps to address your problem concerning missing passwords.